TUCSON – At the grocery store where a gunman gravely injured her and killed six others, former U.S. Rep. Gabrielle Giffords and other survivors called Wednesday for Congress to pass legislation that would require universal background checks for gun buyers.

Emily Nottingham, Zimmerman’s mother, said it was painful to return to the spot where her son died but that she needed to speak out against what she called loopholes in gun laws.

“The system is riddled with holes, bullet holes, and it needs to be fixed,” she said.

While background checks are required for all purchases from federally licensed gun dealers, the law doesn’t apply to firearms sold at gun shows, online or in private transactions. A bill expected to be voted on Thursday in the Senate Judiciary Committee, of which Republican Jeff Flake of Arizona is a member, would change this.

Randy Gardner, who was shot in the foot in the attack, said requiring background checks is the least the government can do. He said it wouldn’t limit individual rights, as some opponents fear.

“This is not a slippery slope,” Gardner said. “This is more a thoughtful walk across a level ground.”

Retired astronaut Mark Kelly, Giffords’ husband, said he and Giffords have taken up the issue with Flake and Republican Sen. John McCain of Arizona.

McCain spokeswoman Rachael Dean said in a prepared statement that the senior Arizona senator appreciates Giffords’ and Kelly’s leadership on the issue.

“As Senator McCain has said, he strongly supports the bipartisan efforts under way in the Senate to reach an agreement on universal background checks and looks forward to reviewing their legislation when completed,” she wrote.

Flake opposes universal background checks but supports expanding background checks by integrating mental health records into the National Criminal Instant Background Check System, according to a statement issued by his office.

“I applaud Gabby and Mark for their efforts to strengthen background checks for gun purchases, particularly as it relates to including mental health records in the NICS,” it read.

Giffords’ shooter, Jared Lee Loughner, obtained his gun after passing a background check despite having a history of mental illness.

Susan Hileman, who brought Christina Taylor Green to Giffords’ Congress on the Corner event in January 2011 and survived three gunshot wounds, said it’s easy to lament mass shootings such as the ones that occurred in Tucson, Aurora, Colo., and Newtown, Conn.

What matters, she said, is action.

“I think it behooves us to all to act,” Hileman said. “Not just to go home and and your head and say, ‘Oh, wasn’t that touching,’ but to actually do something.”

VIDEO STORY

Former Rep. Gabrielle Giffords, back at the Tucson site where she was shot in 2011, repeated her gun-control message to lawmakers: Be bold, be courageous. Cronkite News' Laura Monte reports on Giffords' call for "commonsense" controls.

Video story by Laura Monte

Former U.S. Rep. Gabrielle Giffords addresses a news conference at which she and other victims of the 2011 mass shooting in Tucson called for universal background checks on gun buyers.

Photo by Julia Shumway

Mark Kelly, husband of former U.S. Rep. Gabrielle Giffords, addresses the news conference.